The parent of First Federal Bank reported its third straight quarterly profit Monday while beefing up its Grand Strand business and cracking into a new market in the Upstate.

North Charleston-based First Financial Holdings Inc. said it earned about $770,000, or 5 cents a share. after subtracting dividend payments on its preferred stock. The company posted a $430,000 loss for the same quarter of 2011. The latest results included a $2.1 million tax-related write-off stemming from First Federal’s recent conversion to a state-chartered commercial bank, ending its 78-year run as a savings and loan association.

First Federal officials spent the weekend at six branches it took over after the close of business Friday, when the owner of Pawleys Island-based Plantation Federal Bank failed. The offices were reopened on Monday as First Federal locations.

Friday’s transaction with the Federal Deposit Insurance Corp. included three Greenville branches that Plantation Federal’s owner ran as First Savers Bank.

Reach John P. McDermott at 937-5572.